Brake Horsepower
Compute brake horsepower from torque and RPM.
About Brake Horsepower
Brake horsepower is the power at the flywheel derived from torque and engine speed. The 5252 constant makes the two units meet at that RPM. Horsepower is engineered torque at speed, so peak torque at low RPM does not tell you how much work the engine can do at high RPM.
Formula
Brake Horsepower
BHP = torque (lb-ft) x RPM / 5252
- 5252
- The RPM where torque and horsepower in lb-ft are numerically equal
Worked example
With the default values below, Brake Horsepower returns Brake Horsepower of 285.6. Change any input above and every figure here is recalculated in your browser.
Inputs used
- Torqueminimum 0 lb-ft
- 300 lb-ft
- Engine RPMminimum 0
- 5,000
Results
- Brake Horsepower
- 285.6
- Torque in N-m
- 406.7
- Power in kW
- 213.0
Step by step
- 1Values used
- 2Brake Horsepower
- 3Brake Horsepower= 285.6
- 4Torque in N-m= 406.7
- 5Power in kW= 213.0
Assumptions and limits
- The result is derived only from the 2 inputs listed above. Anything not among them is not part of the calculation.
- In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
- Figures are rounded for display to 1 decimal place, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.
Frequently Asked Questions
How is Brake Horsepower calculated?
BHP = torque (lb-ft) x RPM / 5252 Brake horsepower is the power at the flywheel derived from torque and engine speed. The 5252 constant makes the two units meet at that RPM.
Why does Brake Horsepower matter?
Horsepower is engineered torque at speed, so peak torque at low RPM does not tell you how much work the engine can do at high RPM.
What values do I need to enter?
This calculator takes 2 inputs: Torque, Engine RPM. The pre-filled defaults are a realistic starting point — replace them with figures from your own environment for a result you can act on.